[Patent document 1] JP-2008-158887 A (corresponding to US-2008/0150707)
Japan's VICS (Vehicle Information and Communication System) has a function to provide an in-vehicle apparatus mounted in a vehicle with traffic information ahead of or around the vehicle via radio wave beacons or optical beacons alongside of roads, when the vehicle approaches the beacons.
In addition, an information provision system is known which provides an occupant of a vehicle with a variety of information by executing wireless communication between an in-vehicle apparatus and an over-road device installed near travel routes of the vehicle (see Patent document 1).
In addition, a navigation apparatus is known which executes a route guidance to a destination by detecting a present position of the vehicle using a GPS receiver etc. and displaying a travel route from the present position to the destination as well as a road map in a display device. In such a navigation apparatus, when approaching a turning point or intersection during executing the route guidance to the destination, an enlarged view of the turning point or intersection is displayed to explicitly indicate the heading direction at the turning point or intersection. Thereby, it becomes easy for the driver or user to run at the turning point or intersection as guided by the navigation apparatus.
It is noted that, in the above VICS system, the information provision position at which the vehicle is provided with the information is limited to the installation positions of the radio wave beacons and optical beacons. That is, to change or increase the positions for the information provision, it is necessary to change or increase the installation positions of the radio wave beacons and optical beacons. Accordingly, there is a technical problem that the change or increase in the information provision positions are not so easy.
In addition, in the information provision system in above Patent document 1, the information provision positions providing the vehicle with the information is limited to the installation positions of the over-road devices. However, since the over-road devices are needed to be installed in roads, the installation positions are carefully considered in order to make the installation number minimum. Accordingly, there is a technical problem that the change or increase in the information provision positions are not so easy.
In addition, in the above navigation apparatus, the image data displayed on the display device is stored in the storage media, such as a HDD and DVD-ROM. Thus, the navigation apparatus executes route guidance by reading the required image data from the storage medium. When the image data stored in the storage medium is not updated successively, there is a possibility that the enlarged view of the turning point or intersection illustrated by the image data comes not to reflect the present state as time elapses.